Earth may be experiencing a sixth mass extinction event

Metro

6 hours ago

Hiyah Zaidi Published June 6, 2025 10:52am Updated June 6, 2025 10:52am Link is copied Comments There is no doubt that humans are changing the Earth. From global warming, to mass migration and many animal species being wiped out altogether, the way the world was is no more. But is all this change actually causing a mass extinction event? (Picture: Getty) It is no surprise that humans will one day be extinct, as nothing lasts forever. It's suggested that around 98% of all the organisms that have ever existed on our planet are now extinct. However, when an organism goes extinct, it is usually replaced by another that has a similar role (Picture: Getty) According to the Natural History Museum, Earth's 'normal' extinction rate is often thought to be somewhere between 0.1 and 1 species per 10,000 species per 100 years, which is known as the background rate of extinction. But at least five times in the last 500 million years there has been something called a mass extinction event (Picture: Getty) A mass extinction event is when species disappear much faster than they are replaced. This is usually defined as around 75% of the world's species being lost in a short period of geological time of less than 2.8 million years. Dr Katie Collins, Curator of Benthic Molluscs at the National History Museum, says: 'It's difficult to identify when a mass extinction may have started and ended. However, there are five big events that we know of, where extinction was much higher than normal background rate, and these are often used to decide whether we are going through a sixth one now.' Past extinction events were caused by extreme temperature changes, sea levels changing or one off events like volcanic eruptions or asteroids hitting the Earth (Picture: Getty) One study, published in the journal PNAS, says yes. It suggests that groups of related species are disappearing at a rate of 35% times higher than the expected rate. And there is no guarantee that humans would survive the extinction event. Co-author Dr Gerardo Ceballos suggests that the whole biosphere of the Earth may change, maybe even into a state where it may be impossible for humanity to endure unless dramatic action is taken. He said: 'Biodiversity will recover but the winners [are] very difficult to predict. Many of the losers in these past mass extinctions were incredibly successful groups' (Picture: Getty) It is undeniable that we are seeing some drastic changes to our planet. Extreme weather such as flooding, wildfires and drought have become more frequent, with data revealing that both 2023 and 2024 became the hottest year on record. But as migration changes, humans are also introducing invasive species that are threatening ecosystems all over the world. Although extinction naturally occurs over hundreds and thousands of years, humans are speeding up this process, which researchers have dubbed as the Holocene extinction (Picture: Getty) However, not all researchers agree. A paper published in Trends in Ecology & Evolution questions if we are really heading towards a mass extinction, as they say that less than 0.1% of Earth's known species have gone extinct in the last 500 years, and that the numbers alone do not support a mass extinction. They said: 'Claiming a sixth mass extinction requires a quantitative criterion, and no plausible scenarios for 75% species loss have been proposed.' They added: 'Current projections of future extinction seem more consistent with ~12–40% species loss, which would be catastrophic but far from the 75% criterion used to argue for a sixth mass extinction' (Picture: Getty)